The combined inelastic neutron scattering (INS) and solid-state dft study of hydrogen-atoms dynamics in kaolinite-dimethylsulfoxide intercalate

Vibrational spectra of two kaolinite-dimethylsulfoxide intercalates, obtained using inelastic neutron scattering (INS), were analyzed with a view to understanding the dynamics of the hydrogen atoms in the structure. The main focus was on the spectral region 0-1700 cm, which is difficult to analyze using optical spectroscopy. The experimental vibrational spectra of kaolinite: dimethylsulfoxide and kaolinite:d6-dimethylsulfoxide collected using two different spectrometers were interpreted by means of the solid-state DFT calculations. Calculated spectra were obtained by both normal-mode analysis and molecular dynamics going beyond the harmonic approximation. The Al-O-H bending modes were found to be spread over the large interval 100 - 1200 cm, with the dominant contributions located between 800 and 1200 cm. The shape of the individual hydrogen spectrum depends on whether or not the respective hydrogen atom is involved in an O-H- • O hydrogen bond and on its strength. The modes corresponding to the in-plane movements of the inner-surface hydrogen atoms are well defined and always appear at the top of the intervals of energy transfer. In contrast, the modes generated by the out-of-plane movements of the hydrogen atoms are spread over large energy intervals extending down to the region of external (lattice) modes. The C-H modes are concentrated mainly in the three regions 1200 - 1450 cm, 800-1100 cm, and 0-400 cm. While the first two regions are typical of the various deformational modes of methyl groups, the low-energy region is populated by the modes corresponding to the movements of the whole dimethylsulfoxide molecule

Recent and future developments on TOSCA at ISIS

TOSCA is a high-resolution neutron spectrometer at the ISIS Pulsed Neutron and Muon Source. The instrument is optimised for broadband vibrational spectroscopy in the 0 – 4000 cm-1 region and it has been operational since 2000. This paper describes how the instrument has been progressively upgraded in the intervening years to enable new science. Future upgrades are outlined

Recent and future developments on TOSCA at ISIS

TOSCA is a high-resolution neutron spectrometer at the ISIS Pulsed Neutron and Muon Source. The instrument is optimised for broadband vibrational spectroscopy in the 0 – 4000 cm-1 region and it has been operational since 2000. This paper describes how the instrument has been progressively upgraded in the intervening years to enable new science. Future upgrades are outlined

High Capacity Ammonia Adsorption in a Robust Metal-Organic Framework Mediated by Reversible Host-Guest Interactions

To understand the exceptional adsorption of ammonia (NH(3)) in MFM-300(Sc) (19.5 mmol g(−1) at 273 K and 1 bar without hysteresis), we report a systematic investigation of the mechanism of adsorption by a combination of in situ neutron powder diffraction, inelastic neutron scattering, synchrotron infrared microspectroscopy, and solid-state (45)Sc NMR spectroscopy. These complementary techniques reveal the formation of reversible host–guest supramolecular interactions, which explains directly the observed excellent reversibility of this material over 90 adsorption–desorption cycles

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

International audienceThe Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

International audienceThe Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations